Trotter and Associates, Inc. developed the 2015 Facility Plan for the City of St. Charles, which created the original scope for the Phase III expansion. At that time, the project included the addition of one raw sewage pump, an upgrade of the biological process for expansion and removal of TN and TP, the construction of an additional tertiary clarifier or construction of tertiary filters, an upgrade of the aerobic digestion process, the addition of onsite sludge dewatering, and 150 days ultimate sludge storage capacity. Since 2015, the scope has evolved due to the age of the equipment (originally installed in 2000) and changes in operational theory and preferences.

Jerry Ruth, P.E., Project Manager, and Elizabeth Heise, Project Engineer, worked closely with the Vissering Construction Company on the $17.6 Million project. The facility was previously permitted for a Design Average Flow of 0.7 MGD. The project expanded the DAF capacity to 1.05 MGD. It also included screening and pumping improvements, biological nutrient removal of Phosphorus and Nitrogen utilizing a 5-Stage Bardenpho design, final clarifier rehabilitation, and aerobic digester rehabilitation.

The scope also includes the construction of a new Tertiary Building to house alum storage and feed systems for phosphorus polishing, a non-potable water system, tertiary disc filters, and UV disinfection; the construction of a Vactor receiving station; the construction of a Sludge Handling Building, and construction of a Sludge Storage Building that will provide a year of storage for the City’s two treatment facilities. The project is funded by a Low-Interest Loan from the Illinois EPA.